As conventional mounting structures for electronic equipment, those of the type which is constructed by mounting an electronic component on a wiring board have been used. For example, in Japanese Unexamined Patent Publication JP-A 2-253941 (1990), there is disclosed a wiring board having a ceramic layer.
In this regard, when a penetrating conductor connected to wiring is formed in the ceramic layer, when the wiring board is subjected to heat, due to the difference in thermal expansion coefficient between the ceramic layer and the penetrating conductor, a thermal stress is applied in between the ceramic layer and the penetrating conductor, wherefore the ceramic layer and the penetrating conductor are likely to separate from each other. As the result of the separation of the ceramic layer and the penetrating conductor, the thermal stress applied in between the ceramic layer and the penetrating conductor tends to be concentrated on a junction between the penetrating conductor and the wiring, wherefore the junction becomes susceptible to a break, and this can lead to deterioration in the electrical reliability of the wiring board.